In many applications, particularly for underwater wellheads, there is a need for electrical connections that can be made-up and taken apart in wet conditions. For wellhead connections, these electrical connections typically transmit electrical power from the surface to underwater equipment such as well heads or well control equipment. The connections can also transmit electrical signals from underwater equipment to the surface for processing.
It is an advantage to be able to make-up and take apart these connections underwater without having to bring equipment or components to the surface.
Currently known, wet, make-break connectors typically employ male and female connectors of various types and shapes. One connector relies on the male connector to push out water that might be located in a receptacle that might affect the transmission of electrical current or signals. Another type of known connector fits into a receptacle with a drain opening in it so that water in the receptacle can drain out as the connector is inserted into place. These connectors tend to be expensive and unreliable.
A commonly-used, wet, make-break connector has a plug and a receptacle that is open at two ends, with mating bands of copper extending axially along both parts. When the plug is stabbed into the receptacle, water will be pushed out the other end and the corresponding bands with contact each other to form an electrical connection. This type of connector has been found useful for low voltage and low current applications, but it is not practical for high voltage and high current usage. This type of connector is also difficult to use because it cannot be connected unless the plug is properly oriented or aligned relative to the receptacle in order for the bands on the plug to mate with bands in the receptacle. This type of connector cannot be used between a tubing hanger and an underwater wellhead, which require annular connector elements that do not have to have any specific orientation.
Additionally, in salt water environments exposed conductors cannot be used unless salt deposits on the contacts and adjacent sealing surfaces are cleaned off in order to prevent the connector from shorting to sea water. This requirement is a challenge because it is difficult to design a subsea connection where the contacts and seals are not exposed to salt water.